Identification of relaxation functions in glass by mean of a simple experiment

This communication discusses the possibility of identifying the shear and structure relaxation functions in inorganic glass by means of a single, simple, and non-intrusive experiment. The latter consists of measuring the thickness variation over time of a glass plate cooled symmetrically from both sides from a temperature above the glass transition temperature down to room temperature. Results with "artificially" created experimental observations suggest that in spite of its simplicity, the thickness variation curve contains sufficient information to identify uniquely the relaxation function parameters using the Levenberg-Marquardt method.